src/mesa/swrast/s_aalinetemp.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.3
   4  *
   5  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /*
  27  * Antialiased line template.
  28  */
  29
  30
  31 /*
  32  * Function to render each fragment in the AA line.
  33  * \param ix  - integer fragment window X coordiante
  34  * \param iy  - integer fragment window Y coordiante
  35  */
  36 static void
  37 NAME(plot)(GLcontext *ctx, struct LineInfo *line, int ix, int iy)
  38 {
  39    const SWcontext *swrast = SWRAST_CONTEXT(ctx);
  40    const GLfloat fx = (GLfloat) ix;
  41    const GLfloat fy = (GLfloat) iy;
  42 #ifdef DO_INDEX
  43    const GLfloat coverage = compute_coveragei(line, ix, iy);
  44 #else
  45    const GLfloat coverage = compute_coveragef(line, ix, iy);
  46 #endif
  47    const GLuint i = line->span.end;
  48
  49    (void) swrast;
  50
  51    if (coverage == 0.0)
  52       return;
  53
  54    line->span.end++;
  55    line->span.array->coverage[i] = coverage;
  56    line->span.array->x[i] = ix;
  57    line->span.array->y[i] = iy;
  58
  59    /*
  60     * Compute Z, color, texture coords, fog for the fragment by
  61     * solving the plane equations at (ix,iy).
  62     */
  63 #ifdef DO_Z
  64    line->span.array->z[i] = (GLuint) solve_plane(fx, fy, line->zPlane);
  65 #endif
  66 #ifdef DO_FOG
  67    line->span.array->attribs[FRAG_ATTRIB_FOGC][i][0] = solve_plane(fx, fy, line->fPlane);
  68 #endif
  69 #ifdef DO_RGBA
  70    line->span.array->rgba[i][RCOMP] = solve_plane_chan(fx, fy, line->rPlane);
  71    line->span.array->rgba[i][GCOMP] = solve_plane_chan(fx, fy, line->gPlane);
  72    line->span.array->rgba[i][BCOMP] = solve_plane_chan(fx, fy, line->bPlane);
  73    line->span.array->rgba[i][ACOMP] = solve_plane_chan(fx, fy, line->aPlane);
  74 #endif
  75 #ifdef DO_INDEX
  76    line->span.array->index[i] = (GLint) solve_plane(fx, fy, line->iPlane);
  77 #endif
  78 #ifdef DO_SPEC
  79    line->span.array->spec[i][RCOMP] = solve_plane_chan(fx, fy, line->srPlane);
  80    line->span.array->spec[i][GCOMP] = solve_plane_chan(fx, fy, line->sgPlane);
  81    line->span.array->spec[i][BCOMP] = solve_plane_chan(fx, fy, line->sbPlane);
  82 #endif
  83 #if defined(DO_TEXVAR)
  84    ATTRIB_LOOP_BEGIN
  85       GLfloat (*attribArray)[4] = line->span.array->attribs[attr];
  86       GLfloat invQ;
  87       if (ctx->FragmentProgram._Active) {
  88          invQ = 1.0F;
  89       }
  90       else {
  91          invQ = solve_plane_recip(fx, fy, line->vPlane[attr]);
  92       }
  93       attribArray[i][0] = solve_plane(fx, fy, line->sPlane[attr]) * invQ;
  94       attribArray[i][1] = solve_plane(fx, fy, line->tPlane[attr]) * invQ;
  95       attribArray[i][2] = solve_plane(fx, fy, line->uPlane[attr]) * invQ;
  96       if (attr < FRAG_ATTRIB_VAR0) {
  97          const GLuint unit = attr - FRAG_ATTRIB_TEX0;
  98          line->span.array->lambda[unit][i]
  99             = compute_lambda(line->sPlane[attr],
 100                              line->tPlane[attr], invQ,
 101                              line->texWidth[attr], line->texHeight[attr]);
 102       }
 103    ATTRIB_LOOP_END
 104 #endif
 105
 106    if (line->span.end == MAX_WIDTH) {
 107 #if defined(DO_RGBA)
 108       _swrast_write_rgba_span(ctx, &(line->span));
 109 #else
 110       _swrast_write_index_span(ctx, &(line->span));
 111 #endif
 112       line->span.end = 0; /* reset counter */
 113    }
 114 }
 115
 116
 117
 118 /*
 119  * Line setup
 120  */
 121 static void
 122 NAME(line)(GLcontext *ctx, const SWvertex *v0, const SWvertex *v1)
 123 {
 124    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 125    GLfloat tStart, tEnd;   /* segment start, end along line length */
 126    GLboolean inSegment;
 127    GLint iLen, i;
 128
 129    /* Init the LineInfo struct */
 130    struct LineInfo line;
 131    line.x0 = v0->win[0];
 132    line.y0 = v0->win[1];
 133    line.x1 = v1->win[0];
 134    line.y1 = v1->win[1];
 135    line.dx = line.x1 - line.x0;
 136    line.dy = line.y1 - line.y0;
 137    line.len = SQRTF(line.dx * line.dx + line.dy * line.dy);
 138    line.halfWidth = 0.5F * ctx->Line._Width;
 139
 140    if (line.len == 0.0 || IS_INF_OR_NAN(line.len))
 141       return;
 142
 143    INIT_SPAN(line.span, GL_LINE, 0, 0, SPAN_XY | SPAN_COVERAGE);
 144
 145    line.xAdj = line.dx / line.len * line.halfWidth;
 146    line.yAdj = line.dy / line.len * line.halfWidth;
 147
 148 #ifdef DO_Z
 149    line.span.arrayMask |= SPAN_Z;
 150    compute_plane(line.x0, line.y0, line.x1, line.y1,
 151                  v0->win[2], v1->win[2], line.zPlane);
 152 #endif
 153 #ifdef DO_FOG
 154    line.span.arrayMask |= SPAN_FOG;
 155    compute_plane(line.x0, line.y0, line.x1, line.y1,
 156                  v0->fog, v1->fog, line.fPlane);
 157 #endif
 158 #ifdef DO_RGBA
 159    line.span.arrayMask |= SPAN_RGBA;
 160    if (ctx->Light.ShadeModel == GL_SMOOTH) {
 161       compute_plane(line.x0, line.y0, line.x1, line.y1,
 162                     v0->color[RCOMP], v1->color[RCOMP], line.rPlane);
 163       compute_plane(line.x0, line.y0, line.x1, line.y1,
 164                     v0->color[GCOMP], v1->color[GCOMP], line.gPlane);
 165       compute_plane(line.x0, line.y0, line.x1, line.y1,
 166                     v0->color[BCOMP], v1->color[BCOMP], line.bPlane);
 167       compute_plane(line.x0, line.y0, line.x1, line.y1,
 168                     v0->color[ACOMP], v1->color[ACOMP], line.aPlane);
 169    }
 170    else {
 171       constant_plane(v1->color[RCOMP], line.rPlane);
 172       constant_plane(v1->color[GCOMP], line.gPlane);
 173       constant_plane(v1->color[BCOMP], line.bPlane);
 174       constant_plane(v1->color[ACOMP], line.aPlane);
 175    }
 176 #endif
 177 #ifdef DO_SPEC
 178    line.span.arrayMask |= SPAN_SPEC;
 179    if (ctx->Light.ShadeModel == GL_SMOOTH) {
 180       compute_plane(line.x0, line.y0, line.x1, line.y1,
 181                     v0->specular[RCOMP], v1->specular[RCOMP], line.srPlane);
 182       compute_plane(line.x0, line.y0, line.x1, line.y1,
 183                     v0->specular[GCOMP], v1->specular[GCOMP], line.sgPlane);
 184       compute_plane(line.x0, line.y0, line.x1, line.y1,
 185                     v0->specular[BCOMP], v1->specular[BCOMP], line.sbPlane);
 186    }
 187    else {
 188       constant_plane(v1->specular[RCOMP], line.srPlane);
 189       constant_plane(v1->specular[GCOMP], line.sgPlane);
 190       constant_plane(v1->specular[BCOMP], line.sbPlane);
 191    }
 192 #endif
 193 #ifdef DO_INDEX
 194    line.span.arrayMask |= SPAN_INDEX;
 195    if (ctx->Light.ShadeModel == GL_SMOOTH) {
 196       compute_plane(line.x0, line.y0, line.x1, line.y1,
 197                     v0->index, v1->index, line.iPlane);
 198    }
 199    else {
 200       constant_plane(v1->index, line.iPlane);
 201    }
 202 #endif
 203 #if defined(DO_TEXVAR)
 204    {
 205       const GLfloat invW0 = v0->win[3];
 206       const GLfloat invW1 = v1->win[3];
 207       line.span.arrayMask |= (SPAN_TEXTURE | SPAN_LAMBDA | SPAN_VARYING);
 208       ATTRIB_LOOP_BEGIN
 209          const GLfloat s0 = v0->attrib[attr][0] * invW0;
 210          const GLfloat s1 = v1->attrib[attr][0] * invW1;
 211          const GLfloat t0 = v0->attrib[attr][1] * invW0;
 212          const GLfloat t1 = v1->attrib[attr][1] * invW1;
 213          const GLfloat r0 = v0->attrib[attr][2] * invW0;
 214          const GLfloat r1 = v1->attrib[attr][2] * invW1;
 215          const GLfloat q0 = v0->attrib[attr][3] * invW0;
 216          const GLfloat q1 = v1->attrib[attr][3] * invW1;
 217          compute_plane(line.x0, line.y0, line.x1, line.y1, s0, s1, line.sPlane[attr]);
 218          compute_plane(line.x0, line.y0, line.x1, line.y1, t0, t1, line.tPlane[attr]);
 219          compute_plane(line.x0, line.y0, line.x1, line.y1, r0, r1, line.uPlane[attr]);
 220          compute_plane(line.x0, line.y0, line.x1, line.y1, q0, q1, line.vPlane[attr]);
 221          if (attr < FRAG_ATTRIB_VAR0) {
 222             const GLuint u = attr - FRAG_ATTRIB_TEX0;
 223             const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
 224             const struct gl_texture_image *texImage = obj->Image[0][obj->BaseLevel];
 225             line.texWidth[attr]  = (GLfloat) texImage->Width;
 226                line.texHeight[attr] = (GLfloat) texImage->Height;
 227          }
 228       ATTRIB_LOOP_END
 229    }
 230 #endif
 231
 232    tStart = tEnd = 0.0;
 233    inSegment = GL_FALSE;
 234    iLen = (GLint) line.len;
 235
 236    if (ctx->Line.StippleFlag) {
 237       for (i = 0; i < iLen; i++) {
 238          const GLuint bit = (swrast->StippleCounter / ctx->Line.StippleFactor) & 0xf;
 239          if ((1 << bit) & ctx->Line.StipplePattern) {
 240             /* stipple bit is on */
 241             const GLfloat t = (GLfloat) i / (GLfloat) line.len;
 242             if (!inSegment) {
 243                /* start new segment */
 244                inSegment = GL_TRUE;
 245                tStart = t;
 246             }
 247             else {
 248                /* still in the segment, extend it */
 249                tEnd = t;
 250             }
 251          }
 252          else {
 253             /* stipple bit is off */
 254             if (inSegment && (tEnd > tStart)) {
 255                /* draw the segment */
 256                segment(ctx, &line, NAME(plot), tStart, tEnd);
 257                inSegment = GL_FALSE;
 258             }
 259             else {
 260                /* still between segments, do nothing */
 261             }
 262          }
 263          swrast->StippleCounter++;
 264       }
 265
 266       if (inSegment) {
 267          /* draw the final segment of the line */
 268          segment(ctx, &line, NAME(plot), tStart, 1.0F);
 269       }
 270    }
 271    else {
 272       /* non-stippled */
 273       segment(ctx, &line, NAME(plot), 0.0, 1.0);
 274    }
 275
 276 #if defined(DO_RGBA)
 277    _swrast_write_rgba_span(ctx, &(line.span));
 278 #else
 279    _swrast_write_index_span(ctx, &(line.span));
 280 #endif
 281 }
 282
 283
 284
 285
 286 #undef DO_Z
 287 #undef DO_FOG
 288 #undef DO_RGBA
 289 #undef DO_INDEX
 290 #undef DO_SPEC
 291 #undef DO_TEXVAR
 292 #undef NAME